This is a brand new trail put together by the Prescott Mountain Biking Alliance. Climb up some single track and then take a 4x4 road up to White Spar. You can link this up with a few other trails in the area to make an awesome ride!
From downtown Prescott take Montezuma (89) South and the White Spar Campground parking lot will be on your left. Cross the road opposite of the parking lot entrance and the trail will be right there.
http://www.singletracks.com/item.php?c=1&i=5058